Currently, the light source used in a backlight module of a TFT-LCD is typically an LED (light emitting diode) for which is featured with energy saving and comparably high performance.
Nevertheless, energy saving is an everlasting drive to the development of the TCT-LCD as the manufacturer is questing a LCD with more energy saving. The LCD with LED has evolved from four LED light sources arranged on four sides of a waveguide, then to two LED light sources arranged on two longitudinal sides of the waveguide. Then the LED light sources are arranged to the two transversal sides of the waveguide. While the manufacturer pushes to a limit, i.e. only one LED light source is arranged on a single transversal side, and which has become a threshold for breaking through.